Statistical evidence links exceptional 1995 Atlantic hurricane season to record sea warming

Tropical cyclones rank above earthquakes as the major geophysical cause of loss of life and property (Bryant, 1991; Houghton, 1994). In the United States alone, the damage bill from mainland landfalling hurricanes over the last 50 years averages $2.0 billion per year (Hebert et al., 1996). Years with high numbers of hurricanes provide new insight on the environmental factors influencing interannual variability; hence the interest in the exceptional 1995 Atlantic season which saw 11 hurricanes and a total of 19 tropical storms, double the 50-year average. While most environmental factors in 1995 were favourable for tropical cyclone development, we show that a factor not fully explored before, the sea surface temperature (SST) was the most significant. For the 10 degrees-20 degrees N, 20 degrees-60 degrees W region where 93% of the anomalous 1995 hurricanes developed, similar to 45 year statistical regressions show that SST is the dominating influence, independent of all known other factors, behind the interannual variance in Atlantic hurricance numbers. With this SST experiencing record warm levels in 1995, 0.66 degrees C above the 1946-1995 mean, these regressions indicate that sea warming explains 61+/-34% of the anomalous hurricane activity in 1995 to 95% confidence

Renormalization group for the probability distribution of magnetic impurities in a random-field ϕ4\phi^4 model

Extending the usual Ginzburg-Landau theory for the random-field Ising model, the possibility of dimensional reduction is reconsidered. A renormalization group for the probability distribution of magnetic impurities is applied. New parameters corresponding to the extra $\phi^4$ coupling constants in the replica Hamiltonian are introduced. Although they do not affect the critical phenomena near the upper critical dimension, they can when dimensions are lowered.Comment: 16 pages, 11 figures, revte

Five-loop \sqrt\epsilon-expansions for random Ising model and marginal spin dimensionality for cubic systems

The \sqrt\epsilon-expansions for critical exponents of the weakly-disordered Ising model are calculated up to the five-loop order and found to possess coefficients with irregular signs and values. The estimate n_c = 2.855 for the marginal spin dimensionality of the cubic model is obtained by the Pade-Borel resummation of corresponding five-loop \epsilon-expansion.Comment: 9 pages, TeX, no figure

From random walk to single-file diffusion

We report an experimental study of diffusion in a quasi-one-dimensional (q1D) colloid suspension which behaves like a Tonks gas. The mean squared displacement as a function of time is described well with an ansatz encompassing a time regime that is both shorter and longer than the mean time between collisions. This ansatz asserts that the inverse mean squared displacement is the sum of the inverse mean squared displacement for short time normal diffusion (random walk) and the inverse mean squared displacement for asymptotic single-file diffusion (SFD). The dependence of the single-file 1D mobility on the concentration of the colloids agrees quantitatively with that derived for a hard rod model, which confirms for the first time the validity of the hard rod SFD theory. We also show that a recent SFD theory by Kollmann leads to the hard rod SFD theory for a Tonks gas.Comment: 4 pages, 4 figure

Making Neutrinos Massive with an Axion in Supersymmetry

The minimal supersymmetric standard model (MSSM) of particle interactions is extended to include three singlet (right-handed) neutrino superfields together with three other singlet superfields. The resulting theory is assumed to be invariant under an anomalous global U(1) (Peccei-Quinn) symmetry with one fundamental mass $m_2$. The soft breaking of supersymmetry at the TeV scale is shown to generate an axion scale $f_a$ of order $m_2$. Neutrino masses are generated by $f_a$ according to the usual seesaw mechanism.Comment: 11 pages, substantially revised with important change

Detailed study of B037 based on {\sl HST} images

B037 is of interest because it is both the most luminous and the most highly reddened cluster known in M31. Images of deep observations and of highly spatial resolutions with the Advanced Camera for Surveys on the {\sl HST} firstly show that this cluster is crossed by a dust lane. Photometric data in the F606W and F814W filters obtained in this paper provide that, colors of ($\rm {F606W-F814W}$) in the dust lane are redder $\sim 0.4$ mags than ones in the other regions of B037. The {\sl HST} images show that, this dust lane seems to be contained in B037, not from the M31 disk or the Milky Way. As we know, the formation of dust requires gas with a rather high metallicity. However, B037 has a low metallicity to be $\rm [Fe/H]=-1.07\pm 0.20$. So, it seems improbable that the observed dust lane is physically associated with B037. It is clear that the origin of this dust lane is worthy of future study. In addition, based on these images, we present the precise variation of ellipticity and position angle, and of surface brightness profile, and determine the structural parameters of B037 by fitting a single-mass isotropic King model. In the F606W filter, we derive the best-fitting scale radius, r_0=0.56\pm0.02\arcsec~(=2.16\pm0.08~\rm{pc}), a tidal radius, r_t=8.6\pm0.4\arcsec~(=33.1\pm1.5~\rm{pc}), and a concentration index $c=\log (r_t/r_0)=1.19\pm0.02$. In the F814W filter, we derive r_0=0.56\pm0.01\arcsec~(=2.16\pm0.04~\rm{pc}), r_t=8.9\pm0.3\arcsec~(=34.3\pm1.2~\rm{pc}), and $c=\log (r_t/r_0)=1.20\pm0.01$. The extinction-corrected central surface brightness is $\mu_0=13.53\pm 0.03~{\rm mag~arcsec^{-2}}$ in the F606W filter, and $12.85\pm 0.03~{\rm mag~arcsec^{-2}}$ in the F814W filter, respectively.Comment: Accepted for Publication in RAA, 13 pages, 5 figures and 7 table

Electromagnetically-Induced-Transparency-Like Effect in the Degenerate Triple-Resonant Optical Parametric Amplifier

We investigate experimentally the absorptive and dispersive properties of triple-resonant optical parametric amplifier OPA for the degenerate subharmonic field. In the experiment, the subharmonic field is utilized as the probe field and the harmonic wave as the pump field. We demonstrate that EIT-like effect can be simulated in the triple-resonant OPA when the cavity line-width for the harmonic wave is narrower than that for the subharmonic field. However, this phenomenon can not be observed in a double-resonant OPA. The narrow transparency window appears in the reflected field. Especially, in the measured dispersive spectra of triple-resonant OPA, a very steep variation of the dispersive profile of the subharmonic field is observed, which can result in a slow light as that observed in atomic EIT medium.Comment: 10 pages, 4 figures, appear in Opt. Let

The M33 Globular Cluster System with PAndAS Data: The Last Outer Halo Cluster?

We use CFHT/MegaCam data to search for outer halo star clusters in M33 as part of the Pan-Andromeda Archaeological Survey (PAndAS). This work extends previous studies out to a projected radius of 50 kpc and covers over 40 square degrees. We find only one new unambiguous star cluster in addition to the five previously known in the M33 outer halo (10 kpc <= r <= 50 kpc). Although we identify 2440 cluster candidates of various degrees of confidence from our objective image search procedure, almost all of these are likely background contaminants, mostly faint unresolved galaxies. We measure the luminosity, color and structural parameters of the new cluster in addition to the five previously-known outer halo clusters. At a projected radius of 22 kpc, the new cluster is slightly smaller, fainter and redder than all but one of the other outer halo clusters, and has g' ~ 19.9, (g'-i') ~ 0.6, concentration parameter c ~ 1.0, a core radius r_c ~ 3.5 pc, and a half-light radius r_h ~ 5.5 pc. For M33 to have so few outer halo clusters compared to M31 suggests either tidal stripping of M33's outer halo clusters by M31, or a very different, much calmer accretion history of M33.Comment: 37 pages, 9 figures. Accepted by the Astrophysical Journa

The CDF dijet excess from intrinsic quarks

The CDF collaboration reported an excess in the production of two jets in association with a $W$. We discuss constraints on possible new particle state interpretations of this excess. The fact of no statistically significant deviation from the SM expectation for {$Z$+dijet} events in CDF data disfavors the new particle explanation. We show that the nucleon intrinsic strange quarks provide an important contribution to the $W$ boson production in association with a single top quark production. Such {$W$+t} single top quark production can contribute to the CDF {$W$+dijet} excess, thus the nucleon intrinsic quarks can provide a possible explanation to the CDF excess in {$W$+dijet} but not in {$Z$+dijet} events.Comment: 4 latex pages, 1 figure. Version for journal publicatio